Apparatus for the re-education of the voice



July 10, 1962 Filed Nov. 21, 1958 A. A. A. TOMATIS 3,043,913

APPARATUS FOR THE RE-EDUCATION OF THE VOICE 2 Sheets-Sheet l Fio'l D ,4 LOW PASS 7 AMPL AMPL. AMPL. OUTPUT CONTROL AMPL. AMPL. DEVICE 1B 13 FREQUENCY y 1962 A. A. A. TOMATIS 3,043,913

APPARATUS FOR THE RE-EDUCATION OF THE VOICE 2 Sheets-Sheet 2 Filed NOV. 21. 1958 ll llllllll lllll Unite The present invention is concerned with a system and apparatus for the re-education of the voice.

As is well-known, the voice emission of a given person depends on his hearing.

An apparatus is already known which enables all frequencies included in the sounds produced by a person to be converted into electrical signals out of which various frequency bands are then separated by means of filters, the ear of the subject being then submitted to sounds of which all components which are traumatising for the larynx (corresponding to a frequency band approximately between 100 and 500 cycles) are eliminated. These sounds are purely laryngeal sounds of the so-called deepened voices. The subjects car will perceive only good quality sounds, that is, those utilizing only resounding cavities without any waste of energy. These goodquality sounds have frequencies for example above 2,000 cycles and comply with the normal process. of hearing due to the emergence of a given band-pass with respect to the ambient noise.

This apparatus has the following drawback; when being emitted, vowels first comprise mainly components between 100 and 500 cycles so that it is necessary to hear in that frequency band to pronounce correctly vowels and to emit the fundamental harmonic. On the other hand, during the emission, two very close but nonsimultaneous phenomena are observed: (a) the formation of the vowel, (b) the tone inherent to each individual. In bad-quality voices likely to develop laryngeal traumae both phenomena take place simultaneously.

It is the essential object of this invention to restore this desirable succession in time and therefore to alleviate the laryngeal function.

The object of the invention is an apparatus for the reeducation of the voice of a patient comprising means to convert into electrical signals the sounds produced by the patient, an input amplifying stage amplifying such signals, a low pass filter element to separate the low frequency signals corresponding to traumatising sound components and a high pass filter element to separate high frequencies corresponding to good quality sounds, an output circuit fed by said filter elements and converting back into sounds the filtered signals, as well as by means to block and unblock successively the low pass filter element and the high pass filter element in such a manner that low frequency signals are first transmitted to the output circuit and that such low frequency signals are immediately followed by high frequency signals.

The means to block and unblock the low pass filter and the high pass filter can be realised in the shape of an auxiliary or control chain connected to the outlet of the input amplifying stage of the apparatus, said control chain comprising amplifiers, means to produce control signals of adequate phase and polarity which are applied at precisely determined times and also for determined durations to the low pass and high pass filters.

In order to unblock one filter while the other is blocked and vice-versa, an asymmetrical time-base circuit can be used in co-operation with reversing means.

A frequency meter is connected to the outlet of they input amplifying stage of the auxiliary 'or control chain so as to measure the frequency of the harmonic which is predominant in the sound produced by the patient atent O and thus enables the progress of re-education to be followed.

Using the re-education process and apparatus according to the invention, it is possible to handle disorders of the timbre and of the rhythm which are both connected to the hearing of the patient. I

It has already been stated above that timbre disorders depend on the hearing; that rhythm disorders should also depend on the hearing is a direct consequence, as shown by Dr. Tomatis, of the fact that one of the two ears has a directing role: the patient aims at a sound with one ear in the same way that objects are aimed at visually with one eye.

This directing ear is always on the right-hand side for right-handed people, and on the left-hand side for lefthanded people and the loss of said directing ear explains various phonation disorders which always affect the rhythm and which can take all forms'from mild sputtermg to severe stammering. I

The loss of the directing ear is not necessarily total but can be only relative. To alleviate phonation disorders, it is thus necessary to compensate the unbalance and to provide artificially to the directing ear an in creased hearing ability so as to enable it to play its predominant role. 4 Hereunder will be described, purely by way of example, a mode of realisation of an apparatus according to the invention with reference to the annexed drawings where:

FIGURE 1 is a block diagram showing the principle of .an apparatus according to the invention;

FIGURE 2 is a wiring diagram of an apparatus according to the invention; and

'FIGURES 3A, B, C, D, E show wave forms in various po nts of the wiring diagram of FIGURE 2.

- As shown in FIGURE 1, a microphone 1 is connected to the first amplifying stage 2, connected in turn to a second amplifying stage 3. The outlet of amplifier 3 is connected on the one hand with an inlet of a low-pass filter element 4 and, on the other hand, with the inlet of a high-pass filter element 5. The filter elements 4 and '5 include, in fact, a filter proper and an amplifier. The outlets of both filter elements 4 and 5 are connected to the common inlet of an amplifying stage 6 the outlet of which is connected to a second amplifying stage 7, the output of which is fed into the output'circuit 8 to which, finally earphones 9 are connected.

All elements: -1, 2, 3, 4, 5, 6, 7, 8, 9, constitute together the main chain of the apparatus.

An amplifier 10 which is connected between the first v amplifier 2 and the second amplifier 3 feeds another amplifier 11 which is in turn connected to the control inlet of a block 12-13, the two outlets of which are respectively connected, by leads 14 and 15 to the control inlets of the lowpass filter element 4 and the high-pass filter element 5.

The elements: 10, 11, 12, 13, constitute together the auxiliary chain or control chain of the low-pass and highpass filters.

A frequency meter 16 isconnected to the outlet of the first amplifier 10 of the control chain.

Hereafter follows a detailed description of a particular mode of realisation according to the invention as shown in FIGURE 2.

The current from the microphone 1 is fed into the input transformer 2a, the secondary winding of which is connected to the control grid of a pentode 2c. The plate of the pentode, is linked to the control grid of the pentode 3c of the second amplifying stage 3. The cathode of the latter pentode 3c is connected to a low-pass filter which consists of a capacitor 4a, a potentiometer 4b and a resistor 4d. The adjustable contact of this potentiometer is connected to the control grid of another amplifying pentode 40, which is part of the low-pass filter element 4; the control grid of that pentode 4c is also connected to a contact 17a which is open in normal operation and enables the control grid of pentode 40 to be .earthed. The same control grid is also connected to lead The cathode of pentode 3c is also connected in parallel to the above-mentioned low-pass filter, to a high-pass filter consisting of capacitor 5a and -a potentiometer 5b, which is connected in series with capacitor 5a. The adjustable contact of potentiometer 5b is connected to the control grid of anamplifying pentode So which is part of the high-pass filter element 5. The control grid of this pentode 5c is also connected to a contact 17b which is normally openand is in turn connected to earth) as well as with lead 15.

Both contacts 17a and 17b are built in the same multiple-contact switch and can be operated simultaneously.

The plates of pentodes 4c and 5c are both connected to the control grid of an amplifying pentode 6c, the plate of which is in turn connected to the control grid of another amplifying pentode 7c, the cathode of which is itself connected to the primary winding of the output transformer 8a. I

The secondary winding of said transformer 8a is connected to an attenuator 8b as well as a reversing switch 80 feeding the earphones 9.

The auxiliary or control chain includes a first amplifying stage 10 comprising a constant gain pentode 100, the control grid of which is connected to the plate of pentode 2c of the first input amplifying stage. The plate of said pentode 100 is in turn connected to the control grid of pentode 11c of the next amplifying stage 11 through a potentiometer 11a which enables the total gain of the control chain to be varied. u

The anode of pentode 11c is connected to one inlet of the block 12 -13 which generates control signals, i.e. to cathode 12b of a twin diode 12a. The plate 12c corresponding to cathode 12b is connected through a resistor 12f to the cathode of a twin triode 13a, said cathode 13b being linked to earth through a capacitor 12g. The plate 120 is also connected to earth through a capacitor 121 and to the grid 130 of the twin triode 13w through a resistor 12k, said grid 130 being also linked to earth through a capacitor 12m. The plate 130! and the cathode 13e of the twin triode 13a are connected to earth, while the grid 13;) is connected to cathode 12d of the twin diode 12a as well as to lead 14. The plate 128, cooperating with the second cathode 12d of twin diode 12a, is connected to a battery cell 12 The plate 13g of the twin triode 13a is connected to a multi-cell battery 12h in series with potentiometer 12i, the sliding contact of which is connected tolead 15. 7 The frequency meter 16 comprises a first amplifying pentode 1611, the control grid of which is connected to the anode of the pentode 100 in the first amplifying stage of the control chain. The plate of said pentode 16a is in turn connected to a control grid of an amplifying pentode 16b, the plate of which is connected through a limiting circuit 16d to the control grid of a third amplifying pentode 160, connected so as to work as a cathode'follower; the output of said pentode 160 is fed to a galvanometer 1612 through a differentiating circuit which consists of potentiometer 16g and capacitor 16).

A The mode of operation of the apparatus shown on FIGURE 2 will now be described with reference to th wave forms shown in FIGURE 3. a

The patient, the voice of whom must be reeducated, gives out sounds which are converted by microphone 1 into electrical signals, the frequency of which corresponds to the fundamental tone plus its various barl monics. The totality of this signal is amplified in the first pentode 2c and the output signal of said pentode is fed on the one hand to the second amplifying stage 3 and, on the other hand, to the first amplifying stage 10 of the auxiliary or control chain.

This signal is amplified again by pentode 30 which isconnected both to low-pass filter 4a, 4b and 4d and to high-pass filter 5a5b. The adjustment of the filters is such as to separate, for example, to 500 cycles frequency band in the low-pass filter and all frequencies above 2,000 cycles in the high-pass filter. The outputs of said filters are respectively fed to the control grids of the, amplifying pentodes 4c and 5c; said control grids are also connected to leads 14 and 15, the corresponding filter elements 4 and 5 being blocked or unblocked according to the voltage which is fed on said leads 14 and 15.

The auxiliary or control chain consisting of elements 10, 11, 12 and 13 is fed with the composite output signal of the first amplifying stage 2, the outlet of which is connected to the control grid of pentode 100. This signal is then amplified again in pentode 110, the gain of which can be adjusted by using potentiometer 11a. The composite output signal of pentode is fed to diode 12b12c, the function of which is to eliminate parasite components, as only signals above a certain volume level are allowed to go through. The resulting signal obtained on plate is then fed to a so-called time-base circuit of the asymmetrical type which includes, among other elements, a triode 13b13c13d and a capacitor 12g.

This asymmetrical time-base circuit works as follows: whenever a signal appears on cathode 12b, a current charges capacitor 12g through diode 12b-12c and resistor 12f which creates a voltage-drop such as to place control grid at a very low negative level. Consequently, the apparent resistance of the valve between cathode 13b and plate 13d is very high. If the output signal of plate 12c disappears or if its intensity is reduced, the capacitor 12g is discharged, grid 130 is brought to a very high positive level and the apparent resistance between plate 13d and cathode 13b is very small with the result that the discharge of capacitor 12g is accelerated, the object of capacitors 121 and 12m is to keep grid 130 at a positive level throughout this discharge.

Diode 12d12e which co-operates with cell 12 acts as a charge limiter to capacitor 12g.

FIGURE 3C shows how the voltage of capacitor 12g varies in relation to time for a given signal emitted by the patient. Normally capacitor 12g is at a voltage equal to 0 volts if no signal is fed through the system. Whenever a signal is produced, the voltage decreases from 0 volts to --V volts during time 1 The voltage is maintained at that value as long as the signal continues i.e. during the whole period t When the signal finishes, capacitor 12g is suddenly discharged during period i and its voltage comes back to the original value of Q volts. The period t is much shorter than the period 13. By way of example, the following experimented values have been found t =0.33l second and t =0.1 second.

The potential of lead 14 follows exactly the variations in the voltage of capacitor 12g. It may be remembered that said lead 14 is also connected to control grid 13 The lead 15 which is connected to the moving contact of potentiometer 12i which is placted in the circuit of plate 13g, thus carries a potential of inverse polarity to that applied to lead 14 as triode 13e, 13f, 13g works as an inverter. The potential variation in lead 15 is shown schematically in FIGURE 3B. It should be noted that when no signal is present, the potential of lead 15 is V volts.

In this manner, leads 14 and 15 carry asymmetrical control signals which are characterised by a slow-rising forward front and a quickly-falling backward front.

Two amplifying pentodes 4c and 5c of filter elements 4 'and 5 are thus respectively unblocked and blocked when no sound is produced by the patient, their control grids being at the same potential as leads 14 and 15; By way of simplification, it is assumed that the composite electrical signal obtained at the outlet of pentode 2c and which corresponds to the sound produced by the patient, consists only of a low frequency sinusoidal signal f (for example, lower than 500 cycles) and a high frequency sinusoidal signal 1; (for example, higher than 2,000 cycles).

When the composite signal corresponding to the sound produced by the patient is simuultaneously fed to the entrances of filter elements 4 and 5, the control grid of pentode 4c is at a potential which is higher than the blocking potential so that said pentode 4c is unblocked. The capacitor 12g begins then to charge itself negatively relating to earth so that the potential of lead 14 and consequently of the control grid of pentode 40 decreases towards a value equal to V vol-ts (see FIGURE 3C).

The filter element 4 thus allows through the low frequency signal f during a very short time which is practically equal to t Simultaneously, the pentode 5c of the high-pass filter element 5, which is normally blocked when no signal is emitted, becomes progressively unblocked when the potential of its control grid grows from -V volts to 0 volts (see FIGURE 3B).

Consequently, low frequency signals f are first transmitted by the low pass filter element 4. The amplitude decreases progressively and tends towards 0 when the potential of the control grid of pentode 40 tends towards a value near to V volts (FIGURE 3D).

Simultaneously, high frequency signals f are first blocked by the high-pass filter element 5 and star-t to pass through with an amplitude which grows progressively as the potential of the control grid of pentode 5c tends towards 0 volts (FIGURE 3E).

In this manner the inlet of the first output amplifier stage 6 is fed with a succession of electrical signals conveniently selected and timed. First and during the time interal t signals are passed which correspond to low frequencies and consequently represent a timbreless voice, such signals being immediately followed by high frequency signals which correspond to good quality harmonics, in other words, to a full-timbre voice. These high frequency signals are transmitted during a time interval t which is much longer and which depends on the time during which the patient holds the note.

This succession of signals is then amplified by a second amplifying output stage 7 and fed to the primary winding of the output transformer 8a. The signals obtained at the secondary winding of said transformer are fed to the earphones '9 through a reversing switch 80. The object of damper 8b is to compensate the level of the output signals according to the attenuation ratio of the directing ear of the patient i.e. the car which is pre-d-ominant when detecting the direction of the sound.

The reversing switch 8 0 enables signals to be sent either to the left ear or to the right ear as the case may be.

The contacts 174: and 1712, which are. normally open in operation, the constitute an integral part of a common multicontact switch, enable the automatic control of filter elements 4 and 5 to be suppressed by earthing the control grids of pentodes 4c and 50. In this case the auxiliary or control chain does not influence any more the main chain, and the filter elements 4 and 5 are both permanently unblocked.

The composite signals obtained at the outlet of the first amplying stage 10 of the auxiliary or control chain i.e. at the plate of pentode 100, are fed to the frequency meter '16. They are successively amplified by pentodes 16a and 16b to be limited in amplitude bylimiter16d before they are fed to the control grid of pentode 16c.

The signals obtained from the cathode of said pentode 160 are then differentiated by the differentiating circuit which comprises the potentiometer 16g and the capacitor 16]. Galvanometer 16c thus indicates the frequency of the predominant harmonic in the signal as obtained at the outlet of stage 10. It is possible to pass a judgment on the progress made by the patient in re-educating his voice by examining the value of this frequency.

It is obvious that the apparatus according to the invention could be realised using other types of elements such as transistors, etc. and not only valves.

What I claim is:

1. Apparatus for the re-education of the voice of a patient comprising a first means for converting into electrical signals the sounds produced by the patient, an input amplying stage electrically connected to said first means for amplying such signals, a low pass filter element connected to receive said amplified signals and to pass the low frequency signals corresponding to vowel sound cornponents and a 'high pass filter element connected in parallel with said low pass filter to receive said amplified signals and to pass the high frequency signals that correspond to good quality sounds that is, those utilizing the resounding cavities to give the tone of the voice, an output circuit connected to and fed by said filter elements and a second means for converting back into sounds the filtered signals, means connected between said first means and said high and low pass filters for first unblocking, when no sound is emitted by the patient, that is when no electric signal occurs, the low pass filter element and for blocking simultaneously the high pass filter element and then, upon occurrence of an electric signal corresponding to a sound produced by the patient, for blocking the low pass filter element and unblocking the high pass filter element.

2. Apparatus for the re-education of the voice of a patient comprising means for converting the sounds produced by the patient into electrical signals, two input amplifying stages electrically connected in series to receive and to amplify such signals, a lowpass filter element connected to receive said amplified signals and for separating and passing the low frequency signals corresponding to vowel sound components and a high-pass filter element connected in parallel with said low pass filter to receive said amplified signals and for separating and passing high frequencies corresponding to good quality sounds, that is, those utilizing the resounding cavities to give the tone of the voice, an output circuit electrically connected to and fed by said filter elements forconverting the filtered signals back into sounds, and an auxiliary or control chain connected between said two input amplifying stages and to said respective filter elements, said control chain comprising one input amplifying stage, and means connected in series to receive the signals from said input amplifying stage for producing, control signals of opposite polarities for alternately blocking said low-pass filter element and the high-pass filter element.

3. Apparatus for the re-education of the voice of a patient comprising means for converting the sounds produced by the patient into electrical signals, an input amplifying stage connected to amplify such signals, a lowpass filter element connected to receive and separate and pass the low frequency signals corresponding to vowel sound components and a high-pass filter element connected in parallel with said low pass filter to receive, separate and pass high frequencies corresponding to good quality sounds, that is, those utilizing the resounding civities to give the tone of the voice, an output circuit connected to and fed by said filter elements for converting the filtered signals back into sounds, an auxiliary or control chain connected to an outlet of the input amplifying stage and having two independent outputs, said control chain comprising one input amplifying stage for further amplifying the signals received from said outlet of the input amplitfying stage, an asymmetrical time-base circuit connected blocked, and vi'ee-ver'sa.

4. Apparatus for the 're-education of the voice of a patient comprisin means for converting the sounds produced by the patient into electrical signals, an input amplifying stage connected to receive and to amplify said signals, a low-pass filter element connected to said amplifying stage to receive, separate and pass the low frequencies of said signals corresponding to vowel sound components, and a high-pass filter element connected in parallel with said low-pass filter to receive, separate and pass the high frequencies of said signals corresponding to good quality sounds, that is, those utilizing the resounding cavities to give the tone of the voice, an output circuit connected to and fed by said filter elements for converting the filtered signals back into sounds, and an auxiliary or control chain connected 'to an outlet of the inputarnplifying stage, said control chain comprising one input amplifying stage and having, two independent outputs and means connected to and fed by said input amplifying stage, said means producing, control signals of opposite polarities, said high-pass filter element and lowpass filter element both including a filter and an amna-tely releasing one filter element while the other is plifying valve with at least one control grid, each control grid being connected to the outlet of the corresponding filter and tothe corresponding output of said means which produces control signals of opposite polarities.

5. Apparatus for the re-education of the voice of a patient comprising means for converting the sounds produced by the patient into electrical signals, an input am- 8 plifying stage connected to receive and to amplify 's'uch signals, a low-pajss filter el'efne'nt connected in series with said input amplifying sta e to receive, separate and pass the low frequencies of said signals corresponding to vowel sound components and a high-pass filter element connected in series to said input amplifying stage and in parallel with said low pass filter element to receive, separate and pass the high frequencies of said signals corresponding to good quality sounds, that is, those utilizing the resounding cavities to give the tone of the voice, an

output circuit connected in series to and fed by said filter elements for converting the filtered signals back into sounds, and an auxiliary or control chain connected to an outlet of the input amplifying stage and to respective inlets of said high and low pass filter element said control chain comprising one input amplifying stage, means fed by said input amplifying stage for producing control signals of opposite polarities which are fed in turn to said respective inlets of said low-pass filter element and'said high-pass filter element, a frequency meter connected to an outlet of the input amplifying stage of the auxiliary or control chain in order to measure the frequency of the harmonic which is predominant in the sound produced by the patient so as to follow the progress of the reeducation of his voice.

Dudley Nov. 16, 1937 Edson et al Sept. 29, 1959 

